This invention relates to a method of conditioning fabric, in particular a method for imparting either fabric softness or improved body to the fabric at the discretion of the user.
Fabric conditioning compositions are known which impart fabric softness to fabrics treated therewith. Fabric softness is a property which is most readily apparent in bulked fabrics such as towelling or woolen articles and manifests itself in a softer feel which is achieved inter alia by reducing the rigidity of the fabric construction and improving lubrication between fibres. Fabric softening compositions generally contain a fabric softening agent which is a water-insoluble nonionic, or more usually a cationic compound having one or more long chain alkyl groups, or a mixture of such compounds.
Fabric conditioning compositions are also known which impart increased body or crispness to fabrics treated therewith. This increased body is often referred to as a drape benefit, improved drape resulting from the deposition of starches, waxes and polymeric materials onto the fibres which stiffens the fabric. Drape imparting compositions commonly contain therefore a film forming polymeric material, such as the latex emulsions formed from the polymerisation of vinyl esters, such as poly(vinyl acetate).
The concepts of fabric softness and improved drape are in many respects contradictory. For this reason it has not previously been possible to offer the consumer a product which will provide both increased fabric softness and improved drape.
Further, where the product is in liquid form, the inclusion of both fabric softening agents and drape imparting agents may generate undesired product properties, such as unacceptably high viscosities. German Patent Application No 2 658 575 (HENKEL) describes a composition containing a quaternary ammonium salt as a cationic softener, an anionic polymer as a drape imparting agent and polyacrylamide as a protective colloid. The use of a protective colloid to reduce the interaction between the cationic softener and the anionic polymer, which might otherwise result in poor product properties and reduced performance, adds to the cost of the product. Further, with a product of this type, all treated fabrics receive the drape benefit. Consequently, bulked fabrics such as towels, for which an increased drape is inappropriate, have to be removed from the treatment medium.
We have now discovered a method which will enable the consumer to achieve ore or other of softening and drape benefits according to the discretion of the user.